The only equivalence that makes some sense today is FoV where it can be used to roughly understand what magnification factor you might perceive based off something you know.

and what does this mean? with magnification comes light loose

I mean equivalence for DoF etc don't really tell someone anything about the image as most shooters have no terms of reference

Given proliferation of small sensor image taking devices even that is becoming pointless.

Not really now that FF body is becoming cheaper to afford and updated with the latest technology as a cropped sensor.

By small Sensor I mean camera phones.! now that proliferation and what your average shooter has as a term of reference the Film shooters from yesteryear are a dying breed (literally) and when were all gone what point a FoV based on a sensor size in the minority.?

I don't see any format as the new nirvana they all have strengths and weakness , at present with the aps-c current pixel density it fits my needs.

A 36-50 Mp FF would also work but not give me any massive gains to what I have today but would set be back £10,000+ in replacement glass.

I expect the Pentax FF to be 24Mp and though I'll watch with interest it won't be on my Christmas list for the reasons I've covered in this thread.